package com.inputabc.ct.v1.util;

import javax.crypto.*;
import javax.crypto.spec.SecretKeySpec;
import java.io.UnsupportedEncodingException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;

/**
 * *
 * AES128 ECB pkcs5
 */
public class AES {

    /**
     * 加密
     *
     * @param content 需要加密的内容
     * @param key  加密密码
     * @return
     */
    public static String key = "(*&^%$;#==$%^&e%^==D#$``%^&5==43$1#@";

    public static byte[] encrypt(String content, String key) {
        try {
            KeyGenerator kgen = KeyGenerator.getInstance("AES");
            kgen.init(128, new java.security.SecureRandom(key.getBytes()));
            SecretKey secretKey = kgen.generateKey();
            byte[] enCodeFormat = secretKey.getEncoded();
            SecretKeySpec secretKeySpec = new SecretKeySpec(enCodeFormat, "AES");
            Cipher cipher = Cipher.getInstance("AES");// 创建密码器
            byte[] byteContent = content.getBytes("UTF-8");
            cipher.init(Cipher.ENCRYPT_MODE, secretKeySpec);// 初始化
            byte[] result = cipher.doFinal(byteContent);
            return result; // 加密
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        } catch (NoSuchPaddingException e) {
            e.printStackTrace();
        } catch (InvalidKeyException e) {
            e.printStackTrace();
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (IllegalBlockSizeException e) {
            e.printStackTrace();
        } catch (BadPaddingException e) {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * 解密
     *
     * @param content 待解密内容
     * @param key     解密密钥
     * @return
     */
    public static byte[] decrypt(byte[] content, String key) {
        try {
            KeyGenerator kgen = KeyGenerator.getInstance("AES");
            kgen.init(128, new java.security.SecureRandom(key.getBytes()));
            SecretKey secretKey = kgen.generateKey();
            byte[] enCodeFormat = secretKey.getEncoded();
            SecretKeySpec secretKeySpec = new SecretKeySpec(enCodeFormat, "AES");
            Cipher cipher = Cipher.getInstance("AES");// 创建密码器
            cipher.init(Cipher.DECRYPT_MODE, secretKeySpec);// 初始化
            byte[] result = cipher.doFinal(content);
            return result; // 加密
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        } catch (NoSuchPaddingException e) {
            e.printStackTrace();
        } catch (InvalidKeyException e) {
            e.printStackTrace();
        } catch (IllegalBlockSizeException e) {
            e.printStackTrace();
        } catch (BadPaddingException e) {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * 字符串加密
     *
     * @param content 要加密的字符串
     * @param key     加密的AES Key
     * @return
     */
    public static String encryptString(String content, String key) {
        return parseByte2HexStr(encrypt(content, key));
    }

    /**
     * 字符串解密
     *
     * @param content 要解密的字符串
     * @param key     解密的AES Key
     * @return
     */
    public static String decryptString(String content, String key) {
        byte[] decryptFrom = parseHexStr2Byte(content);
        byte[] decryptResult = decrypt(decryptFrom, key);
        return new String(decryptResult);
    }


    /**
     * 将16进制转换为二进制
     *
     * @param hexStr
     * @return
     */
    public static byte[] parseHexStr2Byte(String hexStr) {
        if (hexStr.length() < 1)
            return null;
        byte[] result = new byte[hexStr.length() / 2];
        for (int i = 0; i < hexStr.length() / 2; i++) {
            int high = Integer.parseInt(hexStr.substring(i * 2, i * 2 + 1), 16);
            int low = Integer.parseInt(hexStr.substring(i * 2 + 1, i * 2 + 2), 16);
            result[i] = (byte) (high * 16 + low);
        }
        return result;
    }


    /**
     * 将二进制转换成16进制
     *
     * @param buf
     * @return
     */
    public static String parseByte2HexStr(byte buf[]) {
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < buf.length; i++) {
            String hex = Integer.toHexString(buf[i] & 0xFF);
            if (hex.length() == 1) {
                hex = '0' + hex;
            }
            sb.append(hex.toUpperCase());
        }
        return sb.toString();
    }

}